How to Defrost (and Defog) Your Car
by Lori Straus
One of the most annoying things about winter is the extra 5 to 10 minutes that you need to clean off your car. The windshield and windows are perhaps the most annoying, because you must clear them completely so you can see the road. In this blog post, we’ll cover a few defrosting tips and also explain a popular defogging process so that your windows can clear up in as little as a few minutes.
What Not to Do
Let’s start here. You’ll find lots of tips on the Internet, many of them useful, but following some can cause serious damage to your vehicle.
- Don’t use saltwater. Although we all use salt to break up ice on the ground, it can seriously damage your vehicle on the inside and outside. Don’t even entertain this idea.
- Don’t pour hot water on your windows. The temperature difference between the water and the glass will be strong enough that you can crack your glass.
- Don’t leave your vehicle running while you’re still inside getting ready. This includes running back-and-forth to load the vehicle. Times are unfortunately changing and communities across Canada are seeing increasingly more vehicles being stolen because they’re left running in the driveway, unlocked, and with the key in the car.
How to Defrost Your Car
Defrosting your windows and windshield will take you a few minutes. However, the following tips can help speed that time up.
- Regardless of how you defrost your windshield and windows, turn on the heat right away. (Just don’t leave the car alone while it’s running.)
- The windshield is the hardest to defrost. Purchase a windshield cover to prevent the frost from forming, but make sure you can securely fasten it to the vehicle.
- Try mixing one part water to two parts 70% isopropyl alcohol, and keep this spray bottle and a cloth in your vehicle. Alcohol has a much lower freezing temperature than water, so it will break up the ice on your windshield and windows. However, if you have young children in the car, make sure the bottle is well out of reach and that the nozzle is closed.
- A scraper will always work, so long as it’s made to scrape glass. Using objects like credit cards or thin pieces of metal can eventually scratch your glass.
How to Defog Your Car
Defrosting your windows and windshield removes frozen water from the outside of your vehicle. But often fog forms on the inside, especially as the vehicle warms up. This process comes from Mark Rober, who has his master’s in mechanical engineering and worked at NASA for nine years.
- Set your car heater on high and to defrost your windshield and rear window.
- Turn on the air conditioner. This will remove moisture from the air inside your vehicle.
- Turn off air recirculation, because you want to draw in air that has less moisture to absorb the moisture inside the vehicle.
- Open your windows just a crack. This helps exchange humid air from the car with drier air from outside.
If you still have problems with fogging, Rober suggests putting a sock filled with kitty litter in your car by the windshield to help absorb more moisture. You can also rub your windshield with shaving cream to prevent any fogging in the first place.
Although we currently can’t promise you that you’ll never have to defrost your windshield and windows again, the above steps can certainly cut down on the time needed to make your car ready to drive.